Multi-speed transmissions with three interconnected planetary gear sets

ABSTRACT

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets and six torque-transmitting mechanisms. A fixed interconnection continuously connects members of the first, second and third planetary gear sets. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the input shaft, the output shaft, and with the transmission housing, and are operated in combinations of three to establish at least seven forward speed ratios and one reverse speed ratio.

TECHNICAL FIELD

The present invention relates to a family of power transmissions havingthree planetary gear sets that are controlled by six torque-transmittingdevices to provide at least seven forward speed ratios and one reversespeed ratio.

BACKGROUND OF THE INVENTION

Passenger vehicles include a powertrain that is comprised of an engine,multi-speed transmission, and a differential or final drive. Themulti-speed transmission increases the overall operating range of thevehicle by permitting the engine to operate through its torque range anumber of times. The number of forward speed ratios that are availablein the transmission determines the number of times the engine torquerange is repeated. Early automatic transmissions had two speed ranges.This severely limited the overall speed range of the vehicle andtherefore required a relatively large engine that could produce a widespeed and torque range. This resulted in the engine operating at aspecific fuel consumption point during cruising, other than the mostefficient point. Therefore, manually-shifted countershaft transmissionswere the most popular.

With the advent of three- and four-speed automatic transmissions, theautomatic shifting (planetary gear) transmission increased in popularitywith the motoring public. These transmissions improved the operatingperformance and fuel economy of the vehicle. The increased number ofspeed ratios reduces the step size between ratios and therefore improvesthe shift quality of the transmission by making the ratio interchangessubstantially imperceptible to the operator under normal vehicleacceleration.

It has been suggested that the number of forward speed ratios beincreased to six or more. Six-speed transmissions are disclosed in U.S.Pat. No. 4,070,927 issued to Polak on Jan. 31, 1978; U.S. Pat. No.6,071,208 issued to Koivunen on Jun. 6, 2000; U.S. Pat. No. 5,106,352issued to Lepelletier on Apr. 21, 1992; and U.S. Pat. No. 5,599,251issued to Beim and McCarrick on Feb. 4, 1997.

Six-speed transmissions offer several advantages over four-andfive-speed transmissions, including improved vehicle acceleration andimproved fuel economy. While many trucks employ power transmissions,such as Polak, having six or more forward gear ratios, passenger carsare still manufactured with three- and four-speed automatictransmissions and relatively few five or six-speed devices due to thesize and complexity of these transmissions. The Polak transmissionprovides six forward speed ratios with three planetary gear sets, twoclutches, and three brakes. The Koivunen and Beim patents utilize sixtorque-transmitting devices including four brakes and two clutches toestablish six forward speed ratios and a reverse ratio. The Lepelletierpatent employs three planetary gear sets, three clutches and two brakesto provide six forward speeds. One of the planetary gear sets ispositioned and operated to establish two fixed speed input members forthe remaining two planetary gear sets.

Seven-speed transmissions are disclosed in U.S. Pat. No. 4,709,594 toMaeda; U.S. Pat. No. 6,053,839 to Baldwin et. al.; and U.S. Pat. No.6,083,135 to Baldwin et. al. Seven- and eight-speed transmissionsprovide further improvements in acceleration and fuel economy oversix-speed transmissions. However, like the six-speed transmissionsdiscussed above, the development of seven- and eight-speed transmissionshas been precluded because of complexity, size and cost.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved familyof transmissions having three planetary gear sets controlled to provideat least seven forward speed ratios and one reverse speed ratio.

In one aspect of the present invention, the family of transmissions hasthree planetary gear sets, each of which includes a first, second andthird member, which members may comprise a sun gear, a ring gear, or aplanet carrier assembly member.

In referring to the first, second and third gear sets in thisdescription and in the claims, these sets may be counted “first” to“third” in any order in the drawings (i.e., left to right, right toleft, etc.).

In another aspect of the present invention, each of the planetary gearsets may be of the single pinion-type or of the double pinion-type.

In yet another aspect of the present invention, the first member of thefirst planetary gear set is continuously interconnected to the firstmember of the second planetary gear set and the first member of thethird planetary gear set through an interconnecting member.

In yet a further aspect of the invention, each family memberincorporates an output shaft which is continuously connected with amember of the planetary gear sets and an input shaft which iscontinuously connected with another member of the planetary gear sets.

In a further aspect of the invention, a first torque-transmittingmechanism, such as a brake, selectively interconnects a member of thefirst, second or third planetary gear set with the transmission housing.

In still a further aspect of the invention, a second torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst planetary gear set or the interconnecting member with the inputshaft, the output shaft, or a member of the second or third planetarygear set.

In another aspect of the invention, a third torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thesecond planetary gear set or the interconnecting member with the inputshaft, the output shaft, or a member of the first or third planetarygear set.

In a still further aspect of the invention, a fourth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thethird planetary gear set or the interconnecting member with the inputshaft, the output shaft, or a member of the first or second planetarygear set.

In a still further aspect of the invention, a fifth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst, second or third planetary gear set with another member of thefirst, second or third planetary gear set. Alternatively, the fifthtorque-transmitting mechanism, such as a brake, selectivelyinterconnects a member of the first, second or third planetary gear setwith the transmission housing.

In still another aspect of the invention, a sixth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thesecond or third planetary gear set or the interconnecting member withanother member of the first, second or third planetary gear set.Alternatively, the sixth torque transmitting mechanism, such as a brake,selectively connects a member of the first, second or third planetarygear set with the transmission housing.

In still another aspect of the invention, the six torque-transmittingmechanisms are selectively engageable in combinations of three to yieldat least seven forward speed ratios and one reverse speed ratio.

The above object and other objects, features, and advantages of thepresent invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic representation of a powertrain including aplanetary transmission incorporating a family member of the presentinvention;

FIG. 1b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 1a;

FIG. 2a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 2b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 2a;

FIG. 3a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 3b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 3a;

FIG. 4a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 4b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 4a;

FIG. 5a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 5b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 5a;

FIG. 6a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 6b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 6a;

FIG. 7a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 7b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 7a;

FIG. 8a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 8b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 8a;

FIG. 9a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 9b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 9a;

FIG. 10a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 10b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 10a;

FIG. 11a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 11b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 11a;

FIG. 12a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 12b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 12a;

FIG. 13a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 13b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 13a;

FIG. 14a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 14b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 14a;

FIG. 15a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 15b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 15a;

FIG. 16a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 16b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 16a;

FIG. 17a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 17b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 17a;

FIG. 18a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention; and

FIG. 18b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 18a.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, wherein like characters represent the same orcorresponding parts throughout the several views, there is shown in FIG.1a a powertrain 10 having a conventional engine and torque converter 12,a planetary transmission 14, and a conventional final drive mechanism16.

The planetary transmission 14 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 18, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 18 includesthree planetary gear sets 20, 30 and 40.

The planetary gear set 20 includes a sun gear member 22, a ring gearmember 24, and a planet carrier assembly 26. The planet carrier assembly26 includes a plurality of pinion gears 27 rotatably mounted on acarrier member 29 and disposed in meshing relationship with both the sungear member 22 and the ring gear member 24.

The planetary gear set 30 includes a sun gear member 32, a ring gearmember 34, and a planet carrier assembly member 36. The planet carrierassembly member 36 includes a plurality of pinion gears 37 rotatablymounted on a carrier member 39 and disposed in meshing relationship withboth the sun gear member 32 and the ring gear member 34.

The planetary gear set 40 includes a sun gear member 42, a ring gearmember 44, and a planet carrier assembly member 46. The planet carrierassembly member 46 includes a plurality of pinion gears 47 rotatablymounted on a carrier member 49 and disposed in meshing relationship withboth the sun gear member 42 and the ring gear member 44.

The planetary gear arrangement also includes six torque-transmittingmechanisms 50, 52, 54, 56, 58 and 59. The torque-transmitting mechanisms50, 52 and 54 are rotating-type torque-transmitting mechanisms, commonlytermed clutches. The torque-transmitting mechanisms 56, 58 and 59 arestationary-type torque-transmitting mechanisms, commonly termed brakesor reaction clutches.

The input shaft 17 is continuously connected with the sun gear member22, and the output shaft 19 is continuously connected with the ring gearmember 34. The ring gear member 24 is continuously connected with thesun gear members 32, 42 through the interconnecting member 70.

The planet carrier assembly member 26 is selectively connectable withthe planet carrier assembly member 46 through the clutch 50. The sungear member 22 is selectively connectable with the ring gear member 44through the clutch 52. The planet carrier assembly member 36 isselectively connectable with the ring gear member 44 through the clutch54. The ring gear member 24 is selectively connectable with thetransmission housing 60 through the brake 56. The planet carrierassembly member 26 is selectively connectable with the transmissionhousing 60 through the brake 58. The planet carrier assembly member 36is selectively connectable with the transmission housing 60 through thebrake 59.

As shown in FIG. 1b, and in particular the truth table disclosedtherein, the torque-transmitting mechanisms are selectively engaged incombinations of three to provide seven forward speed ratios and areverse speed ratio. It should also be noted in the truth table that thetorque-transmitting mechanisms 50 and 59 remain engaged through aneutral condition, thereby simplifying the forward/reverse interchange.

The reverse speed ratio is established with the engagement of theclutches 50, 52 and the brake 59. The clutch 50 connects the planetcarrier assembly member 26 to the planet carrier assembly member 36. Theclutch 52 connects the sun gear member 22 to the ring gear member 44.The brake 59 connects the planet carrier assembly member 36 to thetransmission housing 60. The sun gear member 22 and ring gear member 44rotate at the same speed as the input shaft 17. The ring gear member 24rotates at the same speed as the sun gear members 32, 42. The planetcarrier assembly member 26 rotates at the same speed as the planetcarrier assembly member 46. The planet carrier assembly member 36 doesnot rotate. The ring gear member 34 rotates at the same speed as theoutput shaft 19. The ring gear member 34, and therefore the output shaft19, rotates at a speed determined from the speed of the sun gear member32 and the ring gear/sun gear tooth ratio of the planetary gear set 30.The numerical value of the reverse speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 30.

The first forward speed ratio is established with the engagement of theclutch 50 and the brakes 58, 59. The clutch 50 connects the planetcarrier assembly member 26 to the planet carrier assembly member 46. Thebrake 58 connects the planet carrier assembly member 26 to thetransmission housing 60. The brake 59 connects the planet carrierassembly member 36 to the transmission housing 60. The planet carrierassembly members 26, 36 and 46 do not rotate. The sun gear member 22rotates at the same speed as the input shaft 17. The ring gear member 24rotates at the same speed as the sun gear members 32, 42. The ring gearmember 24 rotates at a speed determined from the speed of the sun gearmember 22 and the ring gear/sun gear tooth ratio of the planetary gearset 20. The ring gear member 34 rotates at the same speed as the outputshaft 19. The ring gear member 34, and therefore the output shaft 19,rotates at a speed determined from the speed of the sun gear member 32and the ring gear/sun gear tooth ratio of the planetary gear set 30. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 20 and30.

The second forward speed ratio is established with the engagement of theclutches 50, 54 and the brake 59. The clutch 50 connects the planetcarrier assembly member 26 to the planet carrier assembly member 46. Theclutch 54 connects the planet carrier assembly member 36 to the ringgear member 44. The brake 59 connects the planet carrier assembly member36 to the transmission housing 60. The sun member 22 rotates at the samespeed as the input shaft 17. The ring gear member 24 rotates at the samespeed as the sun gear members 32, 42. The planet carrier assembly member26 rotates at the same speed as the planet carrier assembly member 46.The planet carrier assembly member 26 rotates at a speed determined fromthe speed of the ring gear member 24, the speed of the sun gear member22, and the ring gear/sun gear tooth ratio of the planetary gear set 20.The planet carrier assembly member 36 and ring gear member 44 do notrotate. The ring gear member 34 rotates at the same speed as the outputshaft 19. The ring gear member 34, and therefore the output shaft 19,rotates at a speed determined from the speed of the sun gear member 32and the ring gear/sun gear tooth ratio of the planetary gear set 30. Theplanet carrier assembly member 46 rotates as a speed determined from thespeed of the sun gear member 42 and the ring gear/sun gear tooth ratioof the planetary gear set 40. The numerical value of the second forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 20, 30 and 40.

The third forward speed ratio is established with the engagement of theclutches 50, 54 and the brake 58. The clutch 50 connects the planetcarrier assembly member 26 to the planet carrier assembly member 46. Theclutch 54 connects the planet carrier assembly member 36 to the ringgear member 44. The brake 58 connects the planet carrier assembly member26 to the transmission housing 60. The sun gear member 22 rotates at thesame speed as the input shaft 17. The planet carrier assembly members26, 46 do not rotate. The ring gear member 24 rotates at the same speedas the sun gear members 32, 42. The ring gear member 24 rotates at aspeed determined from the speed of the sun gear member 22 and the ringgear/sun gear tooth ratio of the planetary gear set 20. The ring gearmember 34 rotates at the same speed as the output shaft 19. The planetcarrier assembly member 36 rotates at the same speed as the ring gearmember 44. The ring gear member 34, and therefore the output shaft 19,rotates at a speed determined from the speed of the sun gear member 32 ,the speed of the planet carrier assembly member 36, and the ringgear/sun gear tooth ratio of the planetary gear set 30. The ring gearmember 44 rotates at the speed determined from the speed of the sun gearmember 42 and the ring gear/sun gear tooth ratio of the planetary gearset 40. The numerical value of the third forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 20, 30 and 40.

The fourth forward speed ratio is established with the engagement of theclutches 50, 54 and the brake 56. The clutch 50 connects the planetcarrier assembly member 26 to the planet carrier assembly member 46. Theclutch 54 connects the planet carrier assembly member 36 to the ringgear member 44. The brake 56 connects the ring gear member 24 to thetransmission housing 60. The ring gear member 24 and sun gear members32, 42 do not rotate. The planet carrier assembly member 26 rotates atthe same speed as the planet carrier assembly member 46. The sun gearmember 22 rotates at the same speed as the input shaft 17. The planetcarrier assembly member 26 rotates at a speed determined from the speedof the sun gear member 22 and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The ring gear member 34 rotates at the same speedas the output shaft 19. The planet carrier assembly member 36 rotates atthe same speed as the ring gear member 44. The ring gear member 34, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the planet carrier assembly member 36 and the ring gear/sungear tooth ratio of the planetary gear set 30. The planet carrierassembly member 46 rotates at a speed determined from the speed of thering gear member 44 and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the fourth forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 20, 30 and 40.

The fifth forward speed ratio is established with the engagement of theclutches 50, 52 and 54. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

The sixth forward speed ratio is established with the engagement of theclutches 52, 54 and the brake 56. The clutch 52 connects the sun gearmember 22 to the ring gear member 44. The clutch 54 connects the planetcarrier assembly member 36 to the ring gear member 44. The brake 56connects the ring gear member 24 to the transmission housing 60. Thering gear member 24 and sun gear members 32, 42 do not rotate. The sungear member 22, ring gear member 44, and planet carrier assembly member36 rotate at the same speed as the input shaft 17. The ring gear member34 rotates at the same speed as the output shaft 19. The ring gearmember 34, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the planet carrier assembly member 36 andthe ring gear/sun gear tooth ratio of the planetary gear set 30. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 30.

The seventh forward speed ratio is established with the engagement ofthe clutches 52, 54 and the brake 58. The clutch 52 connects the sungear member 22 to the ring gear member 44. The clutch 54 connects theplanet carrier assembly member 36 to the ring gear member 44. The brake58 connects the planet carrier assembly member 26 to the transmissionhousing 60. The ring gear member 24 rotates at the same speed and thesun gear members 32, 42. The sun gear member 22, ring gear member 44,and planet carrier assembly member 36 rotate at the same speed as theinput shaft 17. The planet carrier assembly member 26 does not rotate.The ring gear member 24 rotates at a speed determined from the speed ofthe sun gear member 22 and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The ring gear member 34 rotates at the same speedas the output shaft 19. The ring gear member 34, and therefore theoutput shaft 19, rotates at a speed determined from the speed of theplanet carrier assembly member 36, the speed of the sun gear member 32,and the ring gear/sun gear tooth ratio of the planetary gear set 30. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets20 and 30.

As set forth above, the engagement schedule for the torque-transmittingmechanisms is shown in the truth table of FIG. 1b. This truth table alsoprovides an example of speed ratios that are available utilizing thering gear/sun gear tooth ratios given by way of example in FIG. 1b. TheR1/S1 value is the tooth ratio of the planetary gear set 20; the R2/S2value is the tooth ratio of the planetary gear set 30; and the R3/S3value is the tooth ratio of the planetary gear set 40. Also, the chartof FIG. 1b describes the ratio steps that are attained utilizing thesample of tooth ratios given. For example, the step ratio between thefirst and second forward speed ratios is 1.85, while the step ratiobetween the reverse and first forward ratio is 0.54. It can also bereadily determined from the truth table of FIG. 1b that all of thesingle step forward ratio interchanges are of the single transitionvariety, as are the double step forward ratio interchanges.

FIG. 2a shows a powertrain 110 having a conventional engine and torqueconverter 12, a planetary transmission 114, and a conventional finaldrive mechanism 16.

The planetary transmission 114 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 118, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 118 includesthree planetary gear sets 120, 130 and 140.

The planetary gear set 120 includes a sun gear member 122, a ring gearmember 124, and a planet carrier assembly 126. The planet carrierassembly 126 includes a plurality of pinion gears 127 rotatably mountedon a carrier member 129 and disposed in meshing relationship with boththe sun gear member 122 and the ring gear member 124.

The planetary gear set 130 includes a sun gear member 132, a ring gearmember 134, and a planet carrier assembly member 136. The planet carrierassembly member 136 includes a plurality of pinion gears 137 rotatablymounted on a carrier member 139 and disposed in meshing relationshipwith both the sun gear member 132 and the ring gear member 134.

The planetary gear set 140 includes a sun gear member 142, a ring gearmember 144, and a planet carrier assembly member 146. The planet carrierassembly member 146 includes a plurality of pinion gears 147 rotatablymounted on a carrier member 149 and disposed in meshing relationshipwith both the sun gear member 142 and the ring gear member 144.

The planetary gear arrangement 118 also includes six torque-transmittingmechanisms 150, 152, 154, 156, 158 and 159. The torque-transmittingmechanisms 150, 152 and 154 are rotating-type torque-transmittingmechanisms, commonly termed “clutches.” The torque-transmittingmechanisms 156, 158 and 159 are stationary-type torque-transmittingmechanisms, commonly termed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member122, and the output shaft 19 is continuously connected with the ringgear member 144. The ring gear member 124 is, continuously connectedwith the planet carrier assembly member 136 and the sun gear member 142through the interconnecting member 170.

The sun gear member 122 is selectively connectable with the planetcarrier assembly member 146 through the clutch 150. The planet carrierassembly member 126 is selectively connectable with the ring gear member134 through the clutch 152. The planet carrier assembly member 126 isselectively connectable with the planet carrier assembly member 146through the clutch 154. The sun gear member 132 is selectivelyconnectable with the transmission housing 160 through the brake 156. Thering gear member 134 is selectively connectable with the transmissionhousing 160 through the brake 158. The planet carrier assembly member146 is selectively connectable with the transmission housing 160 throughthe brake 159.

The truth table of FIG. 2b describes the engagement sequence utilized toprovide seven forward speed ratios and a reverse speed ratio in theplanetary gear arrangement 118 shown in FIG. 2a.

The reverse speed ratio is established with the engagement of the clutch152 and the brakes 156, 159. The clutch 152 connects the planet carrierassembly member 126 to the ring gear member 134. The brake 156 connectsthe sun gear member 132 to the transmission housing 160. The brake 159connects the planet carrier assembly member 146 to the transmissionhousing 160. The sun gear member 122 rotates at the same speed as theinput shaft 17. The planet carrier assembly member 126 rotates at thesame speed as the ring gear member 134. The ring gear member 124 rotatesat the same speed as the planet carrier assembly member 136 and the sungear member 142. The planet carrier assembly member 126 rotates at aspeed determined from the speed of the ring gear member 124, the speedof the sun gear member 122, and the ring gear/sun gear tooth ratio ofthe planetary gear set 120. The sun gear member 132 does not rotate. Theplanet carrier assembly member 136 rotates at a speed determined fromthe speed of the ring gear member 134 and the ring gear/sun gear toothratio of the planetary gear set 130. The planet carrier assembly member146 does not rotate. The ring gear member 144 rotates at the same speedas the output shaft 19. The ring gear member 144, and therefore theoutput shaft 19, rotates at a speed determined from the speed of the sungear member 142 and the ring gear/sun gear tooth ratio of the planetarygear set 140. The numerical value of the reverse speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 120, 130 and 140.

The first forward speed ratio is established with the engagement of theclutch 154 and the brakes 156, 159. The clutch 154 connects the planetcarrier assembly member 126 to the planet carrier assembly member 146.The brake 156 connects the sun gear member 132 to the transmissionhousing 160. The brake 159 connects the planet carrier assembly member146 to the transmission housing 160. The sun gear member 122 rotates atthe same speed as the input shaft 17. The planet carrier assemblymembers 126, 146 do not rotate. The ring gear member 124 rotates at thesame speed as the planet carrier assembly member 136 and the sun gearmember 142. The ring gear member 124 rotates at a speed determined fromthe speed of the sun gear member 122 and the ring gear/sun gear toothratio of the planetary gear set 120. The sun gear member 132 does notrotate. The ring gear member 144 rotates at the same speed as the outputshaft 19. The ring gear member 144, and therefore the output shaft 19,rotates at a speed determined from the speed of the sun gear member 142and the ring gear/sun gear tooth ratio of the planetary gear set 140.The numerical value of the first forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets120 and 140.

The second forward speed ratio is established with the engagement of theclutch 154 and the brakes 156, 158. The clutch 154 connects the planetcarrier assembly member 126 to the planet carrier assembly member 146.The brake 156 connects the sun gear member 132 to the transmissionhousing 160. The brake 158 connects the ring gear member 134 to thetransmission housing 160. The ring gear member 124, planetary gear set130, and the sun gear member 142 do not rotate. The planet carrierassembly member 126 rotates at the same speed as the planet carrierassembly member 146. The sun gear member 122 rotates at the same speedas the input shaft 17. The planet carrier assembly member 126 rotates ata speed determined from the speed of the sun gear member 122 and thering gear/sun gear tooth ratio of the planetary gear set 120. The ringgear member 144 rotates at the same speed as the output shaft 19. Thering gear member 144, and therefore the output shaft 19, rotates at aspeed determined from the speed of the planet carrier assembly member146 and the ring gear/sun gear tooth ratio of the planetary gear set.140. The numerical value of the second forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets120 and 140.

The third forward speed ratio is established with the engagement of theclutches 152, 154 and the brake 156. The clutch 152 connects the planetcarrier assembly member 126 to the ring gear member 134. The clutch 154connects the planet carrier assembly member 126 to the planet carrierassembly member 146. The brake 156 connects the sun gear member 132 tothe transmission housing 160. The sun gear member 122 rotates at thesame speed as the input shaft 17. The ring gear member 124 rotates atthe same speed as the planet carrier assembly member 136 and the sungear member 142. The planet carrier assembly member 126 rotates at thesame speed as the planet carrier assembly member 146 and the ring gearmember 134. The planet carrier assembly member 126 rotates at a speeddetermined from the speed of the ring gear member 124, the speed of thesun gear member 122, and the ring gear/sun gear tooth ratio of theplanetary gear set 120. The sun gear member 132 does not rotate. Theplanet carrier assembly member 136 rotates at a speed determined fromthe speed of the ring gear member 134 and the ring gear/sun gear toothratio of the planetary gear set 130. The ring gear member 144 rotates atthe same speed as the output shaft 19. The ring gear member 144, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the planet carrier assembly member 146, the speed of the sungear member 142, and the ring gear/sun gear tooth ratio of the planetarygear set 140. The numerical value of the third forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 120, 130 and 140.

The fourth forward speed ratio is established with the engagement of theclutches 150, 154 and the brake 156. In this configuration, the inputshaft 17 is directly connected to the output shaft 19. The numericalvalue of the fourth forward speed ratio is 1.

The fifth forward speed ratio is established with the engagement of theclutches 150, 152 and the brake 156. The clutch 150 connects the sungear member 122 to the planet carrier assembly member 146. The clutch152 connects the planet carrier assembly member 126 to the ring gearmember 134. The brake 156 connects the sun gear member 132 to thetransmission housing 160. The sun gear member 122 and planet carrierassembly member 146 rotate at the same speed as the input shaft 17. Theplanet carrier assembly member 126 rotates at the same speed as the ringgear member 134. The ring gear member 124 rotates at the same speed asthe planet carrier assembly member 136 and the sun gear member 142. Theplanet carrier assembly member 126 rotates at a speed determined fromthe speed of the ring gear member 124, the speed of the sun gear member122, and the ring gear/sun gear tooth ratio of the planetary gear set120. The sun gear member 132 does not rotate. The planet carrierassembly member 136 rotates at a speed determined from the speed of thering gear member 134 and the ring gear/sun gear tooth ratio of theplanetary gear set 130. The ring gear member 144 rotates at the samespeed as the output shaft 19. The ring gear member 144, and thereforethe output shaft 19, rotates at a speed determined from the speed of theplanet carrier assembly member 146, the speed of the sun gear member142, and the ring gear/sun gear tooth ratio of the planetary gear set140. The numerical value of the fifth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets120, 130 and 140.

The sixth forward speed ratio is established with the engagement of theclutch 150 and the brakes 156, 158. The clutch 150 connects the sun gearmember 122 to the planet carrier assembly member 146. The brake 156connects the sun gear member 132 to the transmission housing 160. Thebrake 158 connects the ring gear member 134 to the transmission housing160. The sun gear member 122 and planet carrier assembly member 146rotate at the same speed as the input shaft 17. The ring gear member124, planetary gear set 130, and sun gear member 142 do not rotate. Thering gear member 144 rotates at the same speed as the output shaft 19.The ring gear member 144, and therefore the output shaft 19, rotates ata speed determined from the speed of the planet carrier assembly member146, and the ring gear/sun gear tooth ratio of the planetary gear set140. The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set140.

The seventh forward speed ratio is established with the engagement ofthe clutches 150, 152 and the brake 158. The clutch 150 connects the sungear member 122 to the planet carrier assembly member 146. The clutch152 connects the planet carrier assembly member 126 to the ring gearmember 134. The brake 158 connects the ring gear member 134 to thetransmission housing 160. The sun gear member 122 and planet carrierassembly member 146 rotate at the same speed and the input shaft 17. Theplanet carrier assembly member 126 and ring gear member 134 do notrotate. The ring gear member 124 rotates at the same speed as the planetcarrier assembly member 136 and the sun gear member 142. The ring gearmember 124 rotates at a speed determined from the speed of the sun gearmember 122 and the ring gear/sun gear tooth ratio of the planetary gearset 120. The ring gear member 144 rotates at the same speed as theoutput shaft 19. The ring gear member 144, and therefore the outputshaft 19, rotates at a speed determined from the speed of the planetcarrier assembly member 146, the speed of the sun gear member 142, andthe ring gear/sun gear tooth ratio of the planetary gear set 140. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets120 and 140.

As set forth above, the truth table of FIG. 2b describes the engagementsequence of the torque-transmitting mechanisms utilized to provide areverse drive ratio and seven forward speed ratios. It can be readilydetermined from the truth table that all of the single step forwardinterchanges are of the single transition type, as are the double stepforward interchanges. The truth table also provides an example of theratios that can be attained with the family members shown in FIG. 2autilizing the sample tooth ratios given in FIG. 2b. The R1/S1 value isthe tooth ratio of the planetary gear set 120; the R2/S2 value is thetooth ratio of the planetary gear set 130; and the R3/S3 value is thetooth ratio of the planetary gear set 140. Also shown in FIG. 2b are theratio steps between single step ratios in the forward direction as wellas the reverse to first ratio step ratio. For example, the first tosecond step ratio is 2.09.

Turning to FIG. 3a, a powertrain 210 includes the engine and torqueconverter 12, a planetary transmission 214, and a final drive mechanism16. The planetary transmission 214 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 218, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 218 includes three planetary gear sets 220, 230 and 240.

The planetary gear set 220 includes a sun gear member 222, a ring gearmember 224, and a planet carrier assembly 226. The planet carrierassembly 226 includes a plurality of pinion gears 227 rotatably mountedon a carrier member 229 and disposed in meshing relationship with boththe sun gear member 222 and the ring gear member 224.

The planetary gear set 230 includes a sun gear member 232, a ring gearmember 234, and a planet carrier assembly member 236. The planet carrierassembly member 236 includes a plurality of pinion gears 237 rotatablymounted on a carrier member 239 and disposed in meshing relationshipwith both the sun gear member 232 and the ring gear member 234.

The planetary gear set 240 includes a sun gear member 242, a ring gearmember 244, and a planet carrier assembly member 246. The planet carrierassembly member 246 includes a plurality of pinion gears 247 rotatablymounted on a carrier member 249 and disposed in meshing relationshipwith both the sun gear member 242 and the ring gear member 244.

The planetary gear arrangement 218 also includes six torque-transmittingmechanisms 250, 252, 254, 256, 258 and 259. The torque-transmittingmechanisms 250, 252 and 254 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms256, 258 and 259 are stationary type torque-transmitting mechanisms,commonly termed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member232, and the output shaft 19 is continuously connected with the ringgear member 244. The ring gear member 224 is continuously connected withthe ring gear member 234 and the planet carrier assembly member 246through the interconnecting member 270.

The planet carrier assembly member 226 is selectively connectable withthe sun gear member 232 through the clutch 250. The planet carrierassembly member 226 is selectively connectable with the sun gear member242 through the clutch 252. The planet carrier assembly member 236 isselectively connectable with the ring gear member 244 through the clutch254. The planet carrier assembly member 246 is selectively connectablewith the transmission housing 260 through the brake 256. The sun gearmember 222 is selectively connectable with the transmission housing 260through the brake 258. The sun gear member 242 is selectivelyconnectable with the transmission housing 260 through the brake 259.

As shown in the truth table in FIG. 3b, the torque-transmittingmechanisms are engaged in combinations of three to establish sevenforward speed ratios and one reverse ratio.

The reverse speed ratio is established with the engagement of theclutches 250, 252 and the brake 256. The clutch 250 connects the planetcarrier assembly member 226 to the sun gear member 232. The clutch 252connects the planet carrier assembly member 226 to the sun gear member242. The brake 256 connects the planet carrier assembly member 246 tothe transmission housing 260. The planet carrier assembly member 226 andsun gear members 232, 242 rotate at the same speed as the input shaft17. The ring gear members 224, 234 and planet carrier assembly member246 do not rotate. The ring gear member 244 rotates at the same speed asthe output shaft 19. The ring gear member 244, and therefore the outputshaft 19, rotates at a speed determined from the speed of the sun gearmember 242 and the ring gear/sun gear tooth ratio of the planetary gearset 240. The numerical value of the reverse speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set240.

The first forward speed ratio is established with the engagement of theclutches 252, 254 and the brakes 256. The clutch 252 connects the planetcarrier assembly member 226 to the sun gear member 242. The clutch 254connects the planet carrier assembly member 236 to the ring gear member244. The brake 256 connects the planet carrier assembly member 246 tothe transmission housing 260. The ring gear members 224, 234 and planetcarrier assembly member 246 do not rotate. The planet carrier assemblymember 226 rotates at the same speed as the sun gear member 242. The sungear member 232 rotates at the same speed as the input shaft 17. Theplanet carrier assembly member 236 and ring gear member 244 rotate atthe same speed as the output shaft 19. The planet carrier assemblymember 236 rotates at a speed determined from the speed of the sun gearmember 232 and the ring gear/sun gear tooth ratio of the planetary gearset 230. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 230.

The second forward speed ratio is established with the engagement of theclutches 252, 254 and the brake 259. The clutch 252 connects the planetcarrier assembly member 226 to the sun gear member 242. The clutch 254connects the planet carrier assembly member 236 to the ring gear member244. The brake 259 connects the sun gear member 242 to the transmissionhousing 260. The planet carrier assembly member 226 and sun gear member242 do not rotate. The ring gear members 224, 234 rotate at the samespeed as the planet carrier assembly member 246. The sun gear member 232rotates at the same speed as the input shaft 17. The planet carrierassembly member 236 and ring gear member 244 rotate at the same speed asthe output shaft 19. The planet carrier assembly member 236 rotates at aspeed determined from the speed of the ring gear member 234, the speedof the sun gear member 232, and the ring gear/sun gear tooth ratio ofthe planetary gear set 230. The ring gear member 234, and therefore theoutput shaft 19, rotates at a speed determined from the speed of theplanet carrier assembly member 246 and the ring gear/sun gear toothratio of the planetary gear set 240. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 230 and 240.

The third forward speed ratio is established with the engagement of theclutches 252, 254 and the brake 258. The clutch 252 connects the planetcarrier assembly member 226 to the sun gear member 242. The clutch 254connects the planet carrier assembly member 236 to the ring gear member244. The brake 258 connects the sun gear member 222 to the transmissionhousing 260. The sun gear member 222 does not rotate. The planet carrierassembly member 226 rotates at the same speed as the sun gear member242. The ring gear members 224, 234 rotate at the same speed as theplanet carrier assembly member 246. The planet carrier assembly member226 rotates at a speed determined from the speed of the ring gear member224 and the ring gear/sun gear tooth ratio of the planetary gear set220. The sun gear member 232 rotates at the same speed as the inputshaft 17. The planet carrier assembly member 236 and ring gear member244 rotate at the same speed as the output shaft 19. The planet carrierassembly member 236 rotates at a speed determined from the speed of thesun gear member 232, the speed of the ring gear member 234, and the ringgear/sun gear tooth ratio of the planetary gear set 230. The ring gearmember 244, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the planet carrier assembly member 246, thespeed of the sun gear member 242, and the ring gear/sun gear tooth ratioof the planetary gear set 240. The numerical value of the third forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 220, 230 and 240.

The fourth forward speed ratio is established with the engagement of theclutches 250, 252 and 254. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefourth forward speed ratio is 1.

The fifth forward speed ratio is established with the engagement of theclutches 250, 254 and the brake 258. The clutch 250 connects the planetcarrier assembly member 226 to the sun gear member 232. The clutch 254connects the planet carrier assembly member 236 to the ring gear member244. The brake 258 connects the sun gear member 222 to the transmissionhousing 260. The sun gear member 222 does not rotate. The planet carrierassembly member 226 and sun gear member 232 rotate at the same speed asthe input shaft 17. The ring gear members 224 and 234 rotate at the samespeed as the planet carrier assembly member 246. The planet carrierassembly member 226 rotates at a speed determined from the speed of thering gear member 224, and the ring gear/sun gear tooth ratio of theplanetary gear set 220. The planet carrier assembly member 236 rotatesat the same speed as the ring gear member 244 and the output shaft 19.The planet carrier assembly member 236 rotates at a speed determinedfrom the speed of the ring gear member 234, the speed of the sun gearmember 232, and the ring gear/sun gear tooth ratio of the planetary gearset 230. The ring gear member 244, and therefore the output shaft 19,rotates at a speed determined from the speed of the planet carrierassembly member 246, the speed of the sun gear member 242, and the ringgear/sun gear tooth ratio of the planetary gear set 240. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 220, 230 and 240.

The sixth forward speed ratio is established with the engagement of theclutches 250, 252 and the brake 258. The clutch 250 connects the planetcarrier assembly member 226 to the sun gear member 232. The clutch 252connects the planet carrier assembly member 226 to the sun gear member242. The brake 258 connects the sun gear member 222 to the transmissionhousing 260. The sun gear member 222 does not rotate. The planet carrierassembly member 226 and sun gear members 232, 242 rotate at the samespeed as the input shaft 17. The ring gear members 224, 234 rotate atthe same speed as the planet carrier assembly member 246. The ring gearmember 224 rotates at a speed determined from the speed of the planetcarrier assembly member 226 and the ring gear/sun gear tooth ratio ofthe planetary gear set 220. The ring gear member 244 rotates at the samespeed as the output shaft 19. The ring gear member 244, and thereforethe output shaft 19, rotates at a speed determined from the speed of theplanet carrier assembly member 246, the speed of the sun gear member242, and the ring gear/sun gear tooth ratio of the planetary gear set240. The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets220 and 240.

The seventh forward speed ratio is established with the engagement ofthe clutch 250 and the brakes 258, 259. The clutch 250 connects theplanet carrier assembly member 226 to the sun gear member 232. The brake258 connects the sun gear member 222 to the transmission housing 260.The brake 259 connects the sun gear member 242 to the transmissionhousing 260. The sun gear member 222 does not rotate. The planet carrierassembly member 226 and sun gear member 232 rotate at the same speed asthe input shaft 17. The ring gear members 224, 234 rotate at the samespeed as the planet carrier assembly member 246. The planet carrierassembly member 226 rotates at a speed determined from the speed of thering gear member 224 and the ring gear/sun gear tooth ratio of theplanetary gear set 220. The sun gear member 242 does not rotate. Thering gear member 244 rotates at the same speed as the output shaft 19.The ring gear member 244, and therefore the output shaft 19, rotates ata speed determined from the speed of the planet carrier assembly member246, and the ring gear/sun gear tooth ratio of the planetary gear set240. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 220 and 240.

As previously set forth, the truth table of FIG. 3b describes thecombinations of engagements utilized for the seven forward speed ratiosand reverse ratio. The truth table also provides an example of speedratios that are available with the family member described above. Theseexamples of speed ratios are determined utilizing the tooth ratios givenin FIG. 3b. The R1/S1 value is the tooth ratio of the planetary gear set220; the R2/S2 value is the tooth ratio of the planetary gear set 230;and the R3/S3 value is the tooth ratio of the planetary gear set 240.Also depicted in FIG. 3b is a chart representing the ratio steps betweenadjacent forward speed ratios and the reverse speed ratio. For example,the first to second ratio interchange has a step of 1.87. It can also bereadily determined from the truth table of FIG. 3b that all of thesingle step forward ratio interchanges are of the single transitionvariety, as are all of the double step forward interchanges.

A powertrain 310, shown in FIG. 4a, includes the engine and torqueconverter 12, a planetary transmission 314, and the final drivemechanism 16. The planetary transmission 314 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 318, and output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 318 includes three planetary gear sets 320, 330 and 340.

The planetary gear set 320 includes a sun gear member 322, a ring gearmember 324, and a planet carrier assembly member 326. The planet carrierassembly member 326 includes a plurality of pinion gears 327 rotatablymounted on a carrier member 329 and disposed in meshing relationshipwith both the sun gear member 322 and the ring gear member 324.

The planetary gear set 330 includes a sun gear member 332, a ring gearmember 334, and a planet carrier assembly member 336. The planet carrierassembly member 336 includes a plurality of pinion gears 337 rotatablymounted on a carrier member 339 and disposed in meshing relationshipwith both the sun gear member 332 and the ring gear member 334.

The planetary gear set 340 includes a sun gear member 342, a ring gearmember 344, and a planet carrier assembly member 346. The planet carrierassembly member 346 includes a plurality of pinion gears 347 rotatablymounted on a carrier member 349 and disposed in meshing relationshipwith both the sun gear member 342 and the ring gear member 344.

The planetary gear arrangement 318 also includes six torque-transmittingmechanisms 350, 352, 354, 356, 358 and 359. The torque-transmittingmechanisms 350, 352 and 354 are of the rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanism356, 358 and 359 are stationary type torque-transmitting mechanisms,commonly termed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member322, and the output shaft 19 is continuously connected with the sun gearmember 342. The planet carrier assembly member 326 is continuouslyconnected with the planet carrier assembly member 336 and the ring gearmember 344 through the interconnecting member 370.

The sun gear member 322 is selectively connectable with the planetcarrier assembly member 346 through the clutch 350. The ring gear member324 is selectively connectable with the sun gear member 332 through theclutch 352. The ring gear member 334 is selectively connectable with theplanet carrier assembly member 346 through the clutch 354. The sun gearmember 332 is selectively connectable with the transmission housing 360through the brake 356. The ring gear member 334 is selectivelyconnectable with the transmission housing 360 through the brake 358. Theplanet carrier assembly member 346 is selectively connectable with thetransmission housing 360 through the brake 359.

The truth tables given in FIGS. 4b, 5 b, 6 b, 7 b, 8 b, 9 b, 10 b, 11 b,12 b, 13 b, 14 b, 15 b, 16 b, 17 b and 18 b show the engagementsequences for the torque-transmitting mechanisms to provide at leastseven forward speed ratios and one reverse speed ratio. As shown anddescribed above for the configuration in FIGS. 1a, 2 a and 3 a, thoseskilled in the art will understand from the respective truth tables howthe speed ratios are established through the planetary gear setsidentified in the written description.

The truth table shown in FIG. 4b describes the engagement combinationand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 4b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 4b. The R1/S1 value is the tooth ratio for the planetary gear set320; the R2/S2 value is the tooth ratio for the planetary gear set 330;and the R3/S3 value is the tooth ratio for the planetary gear set 340.Also given in FIG. 4b is a chart describing the step ratios between theadjacent forward speed ratios and the reverse to first forward speedratio. For example, the first to second forward speed ratio step is1.54. It can be readily determined from the truth table of FIG. 4b thateach of the forward single step ratio interchanges is a singletransition shift, as are the double step interchanges. The chart alsoshows that the torque-transmitting mechanisms 352 and 359 can be engagedthrough the neutral condition to simplify the forward/reverseinterchange.

Those skilled in the art will recognize that the numerical values of thereverse and fifth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 320 and 340. Thenumerical values of the first, second and seventh forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 320, 330 and 340. The numerical value of the thirdforward speed ratio is 1. The numerical value of the fourth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear sets 330 and 340. The numerical value of the sixthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 340.

A powertrain 410, shown in FIG. 5a, includes the engine and torqueconverter 12, a planetary transmission 414 and the final drive mechanism16. The planetary transmission 414 includes a planetary gear arrangement418, input shaft 17 and output shaft 19. The planetary gear arrangement418 includes three simple planetary gear sets 420, 430 and 440.

The planetary gear set 420 includes a sun gear member 422, a ring gearmember 424, and a planet carrier assembly 426. The planet carrierassembly 426 includes a plurality of pinion gears 427 rotatably mountedon a carrier member 429 and disposed in meshing relationship with boththe sun gear member 422 and the ring gear member 424.

The planetary gear set 430 includes a sun gear member 432, a ring gearmember 434, and a planet carrier assembly member 436. The planet carrierassembly member 436 includes a plurality of pinion gears 437 rotatablymounted on a carrier member 439 and disposed in meshing relationshipwith both the sun gear member 432 and the ring gear member 434.

The planetary gear set 440 includes a sun gear member 442, a ring gearmember 444, and a planet carrier assembly member 446. The planet carrierassembly member 446 includes a plurality of pinion gears 447 rotatablymounted on a carrier member 449 and disposed in meshing relationshipwith both the sun gear member 442 and the ring gear member 444.

The planetary gear arrangement 418 also includes six torque-transmittingmechanisms 450, 452, 454, 456, 458 and 459. The torque-transmittingmechanisms 450, 452 and 454 are rotating-type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms456, 458 and 459 are stationary-type torque-transmitting mechanisms,commonly termed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member422, and the output shaft 19 is continuously connected with the sun gearmember 442. The planet carrier assembly member 426 is continuouslyconnected with the planet carrier assembly member 436 and the ring gearmember 444 through the interconnecting member 470.

The sun gear member 422 is selectively connectable with the planetcarrier assembly member 446 through the clutch 450. The ring gear member424 is selectively connectable with the sun gear member 432 through theclutch 452. The ring gear member 434 is selectively connectable with theplanet carrier assembly member 446 through the clutch 454. The ring gearmember 424 is selectively connectable with the transmission housing 460through brake 456. The sun gear member 432 is selectively connectablewith the transmission housing 460 through the brake 458. The ring gearmember 434 is selectively connectable with the transmission housing 460through the brake 459.

The truth table shown in FIG. 5b describes the engagement combinationand sequence of the torque-transmitting mechanisms 450, 452, 454, 456,458 and 459 that are employed to provide the reverse drive ratio and theseven forward speed ratios. It should be noted that thetorque-transmitting mechanisms 454 and 459 are engaged through theneutral condition to simplify the forward/reverse interchange.

Also given in the truth table of FIG. 5b is a set of numerical valuesthat are attainable with the present invention utilizing the ringgear/sun gear tooth ratios shown. The R1/S1 value is the tooth ratio ofthe planetary gear set 420; the R2/S2 value is the tooth ratio of theplanetary gear set 430; and the R3/S3 value is the tooth ratio of theplanetary gear set 440. As can also be determined from the truth tableof FIG. 5b, the single step forward interchanges are single transitionshifts, as are the double step interchanges in the forward direction.

FIG. 5b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.54.

Those skilled in the art will recognize that the numerical values of thereverse and fifth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 420 and 440. Thenumerical values of the first, second and seventh forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 420, 430 and 440. The numerical value of the thirdforward speed ratio is 1. The numerical value of the fourth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 430 and 440. The numerical value of the sixthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 440.

A powertrain 510, shown in FIG. 6a, includes an engine and torqueconverter 12, a planetary gear transmission 514 and the final drivemechanism 16. The planetary transmission 514 includes the input shaft17, a planetary gear arrangement 518 and the output shaft 19. Theplanetary gear arrangement 518 includes three planetary gear sets 520,530 and 540.

The planetary gear set 520 includes a sun gear member 522, a ring gearmember 524, and a planet carrier assembly 526. The planet carrierassembly 526 includes a plurality of pinion gears 527 rotatably mountedon a carrier member 529 and disposed in meshing relationship with boththe sun gear member 522 and the ring gear member 524.

The planetary gear set 530 includes a sun gear member 532, a ring gearmember 534, and a planet carrier assembly member 536. The planet carrierassembly member 536 includes a plurality of pinion gears 537 rotatablymounted on a carrier member 539 and disposed in meshing relationshipwith both the sun gear member 532 and the ring gear member 534.

The planetary gear set 540 includes a sun gear member 542, a ring gearmember 544, and a planet carrier assembly member 546. The planet carrierassembly member 546 includes a plurality of pinion gears 547 rotatablymounted on a carrier member 549 and disposed in meshing relationshipwith both the sun gear member 542 and the ring gear member 544.

The planetary gear arrangement 518 also includes six torque-transmittingmechanisms 550, 552, 554, 556, 558 and 559. The torque-transmittingmechanisms 550, 552, 554 and 556 are rotating-type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanism558 and 559 are stationary-type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member542, and the output shaft 19 is continuously connected with the ringgear member 524. The sun gear member 522 is continuously connected withthe ring gear member 534 and the planet carrier assembly member 546through the interconnecting member 570.

The planet carrier assembly member 546 is selectively connectable withthe sun gear member 542 through the clutch 550. The planet carrierassembly member 526 is selectively connectable with the planet carrierassembly member 536 through the clutch 552. The planet carrier assemblymember 526 is selectively connectable with the sun gear member 542through the clutch 554. The planet carrier assembly member 536 isselectively connectable with the ring gear member 544 through the clutch556. The sun gear member 532 is selectively connectable with thetransmission housing 560 through the brake 558. The ring gear member 544is selectively connectable with the transmission housing 560 through thebrake 559.

The truth table shown in FIG. 6b describes the engagement sequence andcombination of the torque-transmitting mechanisms to provide the reversespeed ratio and seven forward speed ratios. It should be noted that thetorque-transmitting mechanisms 552 and 559 can remain engaged throughthe neutral condition, thereby simplifying the forward/reverseinterchange. It can also be determined from the truth table of FIG. 6bthat all of the single step forward ratio interchanges are of the singletransition variety, as are all of the double step forward interchanges.The chart of FIG. 6b describes the ratio steps between adjacent forwardspeed ratios and the ratio step between the reverse and first forwardspeed ratio.

Those skilled in the art, upon reviewing the truth table and theschematic representation of FIG. 6a, can determine that the numericalvalues of the reverse and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets520 and 540. The numerical values of the first, second and sixth forwardspeed ratios are determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 520, 530 and 540. The numerical valuesof the third and fourth forward speed ratio are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 520 and 530.The numerical value of the fifth forward speed ratio is 1.

The sample speed ratios given in the truth table are determinedutilizing the tooth ratio values also given in FIG. 6b. The R1/S1 valueis the tooth ratio of the planetary gear set 520; the R2/S2 value is thetooth ratio of the planetary gear set 530; and the R3/S3 value is thetooth ratio of the planetary gear set 540.

A powertrain 610, shown in FIG. 7a, has the engine and torque converter12, a planetary transmission 614 and the final drive mechanism 16. Theplanetary transmission 614 includes the input shaft 17, a planetary geararrangement 618 and the output shaft 19. The planetary gear arrangement618 includes three planetary gear sets 620, 630 and 640.

The planetary gear set 620 includes a sun gear member 622, a ring gearmember 624, and a planet carrier assembly 626. The planet carrierassembly 626 includes a plurality of pinion gears 627 rotatably mountedon a carrier member 629 and disposed in meshing relationship with boththe sun gear member 622 and the ring gear member 624.

The planetary gear set 630 includes a sun gear member 632, a ring gearmember 634, and a planet carrier assembly member 636. The planet carrierassembly member 636 includes a plurality of pinion gears 637 rotatablymounted on a carrier member 639 and disposed in meshing relationshipwith both the sun gear member 632 and the ring gear member 634.

The planetary gear set 640 includes a sun gear member 642, a ring gearmember 644, and a planet carrier assembly member 646. The planet carrierassembly member 646 includes a plurality of pinion gears 647 rotatablymounted on a carrier member 649 and disposed in meshing relationshipwith both the sun gear member 642 and the ring gear member 644.

The planetary gear arrangement 618 also includes six torque-transmittingmechanisms 650, 652, 654, 656, 658 and 659. The torque-transmittingmechanisms 650, 652, 654 and 656 are rotating-type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms658 and 659 are stationary-type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the planet carrierassembly member 646, and the output shaft 19 is continuously connectedwith the planet carrier assembly member 636. The sun gear member 622 iscontinuously connected with the sun gear member 632 and with the ringgear member 644 through the interconnecting member 670.

The planet carrier assembly member 626 is selectively connectable withthe sun gear member 622 through the clutch 650. The planet carrierassembly member 626 is selectively connectable with the ring gear member634 through the clutch 652. The ring gear member 624 is selectivelyconnectable with the planet carrier assembly member 646 through theclutch 654. The ring gear member 624 is selectively connectable with thesun gear member 642 through the clutch 656. The ring gear member 634 isselectively connectable with the transmission housing 660 through thebrake 658. The sun gear member 642 is selectively connectable with thetransmission housing 660 through the brake 659.

The truth table shown in FIG. 7b describes the combination oftorque-transmitting mechanism engagements that will provide the reversedrive ratio and seven forward speed ratios, as well as the sequence ofthese engagements and interchanges. The torque-transmitting mechanisms654 and 658 can be engaged through the neutral condition, therebysimplifying the forward/reverse interchange. It can be noted from thetruth table that each of the single step forward interchanges are singletransition ratio changes, as are the double step forward interchanges.

The ratio values given are by way of example and are establishedutilizing the ring gear/sun gear tooth ratios given in FIG. 7b. Forexample, the R1/S1 value is the tooth ratio of the planetary gear set620; the R2/S2 value is the tooth ratio of the planetary gear set 630;and the R3/S3 value is the tooth ratio of the planetary gear set 640.The ratio steps between adjacent forward ratios and the reverse to firstratio are also given in FIG. 7b.

Those skilled in the art will, upon reviewing the truth table of FIG.7b, recognize that the numerical value of the reverse speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 620 and 630. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 630. The numerical values of the secondand seventh forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear set 630 and 640. Thenumerical values of the third, fourth and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 620, 630 and 640. The numerical value of the fifthforward speed ratio is 1.

A powertrain 710, shown in FIG. 8a, has the conventional engine andtorque converter 12, a planetary transmission 714, and the conventionalfinal drive mechanism 16. The engine and torque converter 12 aredrivingly connected with the planetary transmission 714 through theinput shaft 17. The planetary transmission 714 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 714 includes a planetary gear arrangement 718that has a first planetary gear set 720, a second planetary gear set730, and a third planetary gear set 740.

The planetary gear set 720 includes a sun gear member 722, a ring gearmember 724, and a planet carrier assembly 726. The planet carrierassembly 726 includes a plurality of pinion gears 727 rotatably mountedon a carrier member 729 and disposed in meshing relationship with boththe sun gear member 722 and the ring gear member 724.

The planetary gear set 730 includes a sun gear member 732, a ring gearmember 734, and a planet carrier assembly member 736. The planet carrierassembly member 736 includes a plurality of pinion gears 737 rotatablymounted on a carrier member 739 and disposed in meshing relationshipwith both the sun gear member 732 and the ring gear member 734.

The planetary gear set 740 includes a sun gear member 742, a ring gearmember 744, and a planet carrier assembly member 746. The planet carrierassembly member 746 includes a plurality of pinion gears 747 rotatablymounted on a carrier member 749 and disposed in meshing relationshipwith both the sun gear member 742 and the ring gear member 744.

The planetary gear arrangement 718 also includes six torque-transmittingmechanisms 750, 752, 754, 756, 758 and 759. The torque-transmittingmechanisms 750, 752, 754 and 756 are rotating-type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms758 and 759 are stationary-type torque-transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member722, and the output shaft 19 is continuously connected with the ringgear member 744. The planet carrier assembly member 726 is continuouslyconnected with the ring gear member 734 and with the sun gear member 742through the interconnecting member 770.

The truth table of FIG. 8b defines the torque-transmitting mechanismengagement sequence utilized for each of the forward speed ratios andthe reverse speed ratio. Also given in the truth table is a set ofnumerical values that are attainable with the present inventionutilizing the ring gear/sun gear tooth ratios given in FIG. 8b. TheR1/S1 value is the tooth ratio of the planetary gear set 720; the R2/S2value is the tooth ratio of the planetary gear set 730; and the R3/S3value is the tooth ratio of the planetary gear set 740. As can also bedetermined from the truth table of FIG. 8b, the single step forwardinterchanges are single transition shifts, as are the double stepinterchanges in the forward direction except the fourth-to-sixth gearstep.

FIG. 8b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.65. Those skilled in the art will recognize that the numerical valuesof the reverse and seventh forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 740. Thenumerical values of the first and fifth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 720, 730 and 740. The numerical values of the secondand third forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the-planetary gear sets 730 and 740. Thenumerical value of the fourth forward speed ratio is 1. The numericalvalue of the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 720 and 740.

A powertrain 810, shown in FIG. 9a, has the conventional engine andtorque converter 12, a planetary transmission 814, and the final drivemechanism 16. The engine and torque converter 12 are drivingly connectedwith the planetary transmission 814 through the input shaft 17. Theplanetary transmission 814 is drivingly connected with the final drivemechanism 16 through the output shaft 19. The planetary transmission 814includes a planetary gear arrangement 818 that has a first planetarygear set 820, a second planetary gear set 830, and a third planetarygear set 840.

The planetary gear set 820 includes a sun gear member 822, a ring gearmember 824, and a planet carrier assembly 826. The planet carrierassembly 826 includes a plurality of pinion gears 827 rotatably mountedon a carrier member 829 and disposed in meshing relationship with boththe sun gear member 822 and the ring gear member 824.

The planetary gear set 830 includes a sun gear member 832, a ring gearmember 834, and a planet carrier assembly member 836. The planet carrierassembly member 836 includes a plurality of pinion gears 837 rotatablymounted on a carrier member 839 and disposed in meshing relationshipwith both the sun gear member 832 and the ring gear member 834.

The planetary gear set 840 includes a sun gear member 842, a ring gearmember 844, and a planet carrier assembly member 846. The planet carrierassembly member 846 includes a plurality of pinion gears 847 rotatablymounted on a carrier member 849 and disposed in meshing relationshipwith both the sun gear member 842 and the ring gear member 844.

The planetary gear arrangement 818 also includes six torque-transmittingmechanisms 850, 852, 854, 856, 858 and 859. The torque-transmittingmechanisms 850, 852, 854 and 856 are of the rotating-typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 858 and 859 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the ring gear member844, and the output shaft 19 is continuously connected with the ringgear member 824. The sun gear member 822 is continuously connected withthe ring gear member 834 and with the planet carrier assembly member 846through the interconnecting member 870.

The planet carrier assembly member 846 is selectively connectable withthe ring gear member 844 through the clutch 850. The planet carrierassembly member 826 is selectively connectable with the planet carrierassembly member 836 through the clutch 852. The planet carrier assemblymember 826 is selectively connectable with the ring gear member 844through the clutch 854. The sun gear member 832 is selectivelyconnectable with the sun gear member 842 through the clutch 856. Theplanet carrier assembly member 836 is selectively connectable with thetransmission housing 860 through the brake 858. The sun gear member 832is selectively connectable with the transmission housing 860 through thebrake 859.

The truth table shown in FIG. 9b defines the torque-transmittingmechanism engagement sequence that provides the reverse ratio and sevenforward speed ratios shown in the truth table and available with theplanetary gear arrangement 818. The truth table indicates that thetorque-transmitting mechanism 852 can remain engaged through the neutralcondition, thereby simplifying the forward/reverse interchange. A sampleof numerical values for the individual ratios is also given in the truthtable of FIG. 9b. These numerical values have been calculated using thering gear/sun gear tooth ratios also given by way of example in FIG. 9b.The R1/S1 value is the tooth ratio of the planetary gear set 820; theR2/S2 value is the tooth ratio of the planetary gear set 830; and theR3/S3 value is the tooth ratio of the planetary gear set 840. It can bereadily recognized from the truth table that all of the single stepforward interchanges are single transition ratio interchanges, exceptthe reverse to first interchange. FIG. 9b also describes the ratio stepsbetween adjacent forward ratios and between the reverse and firstforward ratio. For example, the ratio step between the first and secondforward ratios is 1.54.

Those skilled in the art of planetary transmissions will recognize thatthe numerical values of the reverse and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 820. The numerical values of the first and sixth forward speedratios are determined utilizing the ring gear/sun gear tooth ratios ofthe planetary gear sets 820, 830 and 840. The numerical values of thesecond and third forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 820 and 830. Thenumerical value of the fourth forward speed ratio is 1. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 820 and 840.

The powertrain 910, shown in FIG. 10a, includes the conventional engineand torque converter 12, a planetary transmission 914, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 914 throughthe input shaft 17. The planetary transmission 914 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 914 includes a planetary gear arrangement 918that has a first planetary gear set 920, a second planetary gear set930, and a third planetary gear set 940.

The planetary gear set 920 includes a sun gear member 922, a ring gearmember 924, and a planet carrier assembly 926. The planet carrierassembly 926 includes a plurality of pinion gears 927 that are rotatablymounted on a carrier member 929 and disposed in meshing relationshipwith the sun gear member 922 and the ring gear member 924, respectively.

The planetary gear set 930 includes a sun gear member 932, a ring gearmember 934, and a planet carrier assembly member 936. The planet carrierassembly member 936 includes a plurality of pinion gears 937 rotatablymounted on a carrier member 939 and disposed in meshing relationshipwith both the sun gear member 932 and the ring gear member 934.

The planetary gear set 940 includes a sun gear member 942, a ring gearmember 944, and a planet carrier assembly member 946. The planet carrierassembly member 946 includes a plurality of pinion gears 947 rotatablymounted on a carrier member 949 and disposed in meshing relationshipwith both the sun gear member 942 and the ring gear member 944.

The planetary gear arrangement 918 also includes six torque-transmittingmechanisms 950, 952, 954, 956, 958 and 959. The torque-transmittingmechanisms 950, 952, 954, 956 and 958 are of the rotating-typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 959 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the ring gear member924, and the output shaft 19 is continuously connected with the sun gearmember 942. The sun gear member 922 is continuously connected with thesun gear member 932 and the ring gear member 944 through theinterconnecting member 970.

The ring gear member 924 is selectively connectable with the ring gearmember 934 through the clutch 950. The planet carrier assembly member926 is selectively connectable with the ring gear member 934 through theclutch 952. The planet carrier assembly member 926 is selectivelyconnectable with the sun gear member 942 through the clutch 954. Theplanet carrier assembly member 926 is selectively connectable with theplanet carrier assembly member 946 through the clutch 956. The planetcarrier assembly member 936 is selectively connectable with the planetcarrier assembly member 946 through the clutch 958. The planet carrierassembly member 936 is selectively connectable with the transmissionhousing 960 through the brake 959.

The truth table of FIG. 10b describes the torque-transmitting mechanismengagement sequence utilized to provide the reverse speed ratio andeight forward speed ratios. The truth table also provides a set ofexamples for the ratios for each of the reverse and forward speedratios. These numerical values have been determined utilizing the ringgear/sun gear tooth ratios given in FIG. 10b. The R1/S1 value is thetooth ratio of the planetary gear set 920; the R2/S2 value is the toothratio of the planetary gear set 930; and the R3/S3 value is the toothratio of the planetary gear set 940. It can also be determined from thetruth table of FIG. 10b that each of the forward single step ratiointerchanges are of the single transition variety.

Those skilled in the art, upon reviewing the engagement combinations,will recognize that the numerical values of the reverse and firstforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 920 and 930. The numericalvalues of the second and sixth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets920 and 940. The numerical value of the third forward speed ratio is 1.The numerical values of the fourth, fifth and seventh forward speedratios are determined utilizing the ring gear/sun gear tooth ratios ofthe planetary gear sets 920, 930 and 940. The numerical value of theeighth forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear sets 930 and 940.

A powertrain 1010, shown in FIG. 11a, includes the conventional engineand torque converter 12, a planetary transmission 1014, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1014 through theinput shaft 17. The planetary transmission 1014 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1014 includes a planetary gear arrangement 1018that has a first planetary gear set 1020, a second planetary gear set1030, and a third planetary gear set 1040.

The planetary gear set 1020 includes a sun gear member 1022, a ring gearmember 1024, and a planet carrier assembly 1026. The planet carrierassembly 1026 includes a plurality of pinion gears 1027 rotatablymounted on a carrier member 1029 and disposed in meshing relationshipwith both the sun gear member 1022 and the ring gear member 1024.

The planetary gear set 1030 includes a sun gear member 1032, a ring gearmember 1034, and a planet carrier assembly member 1036. The planetcarrier assembly member 1036 includes a plurality of pinion gears 1037rotatably mounted on a carrier member 1039 and disposed in meshingrelationship with both the sun gear member 1032 and the ring gear member1034.

The planetary gear set 1040 includes a sun gear member 1042, a ring gearmember 1044, and a planet carrier assembly member 1046. The planetcarrier assembly member 1046 includes a plurality of pinion gears 1047rotatably mounted on a carrier member 1049 and disposed in meshingrelationship with both the sun gear member 1042 and the ring gear member1044.

The planetary gear arrangement 1018 also includes sixtorque-transmitting mechanisms 1050, 1052, 1054, 1056, 1058 and 1059.The torque-transmitting mechanisms 1050, 1052, 1054 and 1056 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1058 and 1059 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the planet carrierassembly member 1046, and the output shaft 19 is continuously connectedwith the planet carrier assembly member 1026. The sun gear member 1022is continuously connected with the ring gear member 1034 and the sungear member 1042 through the interconnecting member 1070.

The planet carrier assembly member 1026 is selectively connectable withthe sun gear member 1022 through the clutch 1050. The planet carrierassembly member 1026 is selectively connectable with the planet carrierassembly member 1036 through the clutch 1052. The ring gear member 1024is selectively connectable with the planet carrier assembly member 1046through the clutch 1054. The sun gear member 1032 is selectivelyconnectable with the ring gear member 1044 through the clutch 1056. Thesun gear member 1032 is selectively connectable with the transmissionhousing 1060 through the brake 1058. The planet carrier assembly member1036 is selectively connectable with the transmission housing 1060through the brake 1059.

The truth table shown in FIG. 11b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 11b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 11b. The R1/S1 value is the tooth ratio for the planetary gearset 1020; the R2/S2 value is the tooth ratio for the planetary gear set1030; and the R3/S3 value is the tooth ratio for the planetary gear set1040. Also given in FIG. 11b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse and sixth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratio of the planetary gear sets 1030 and 1040. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 1020,1030 and 1040. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1020. The numerical value of the third forward speed ratiois 1. The numerical value of the fourth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1020 and 1030. The numerical value of the fifthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1020 and 1040. The numerical value ofthe seventh forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 1040.

A powertrain 1110, shown in FIG. 12a, has a conventional engine andtorque converter 12, a planetary transmission 1114, and the conventionalfinal drive mechanism 16. The planetary transmission 1114 includes aplanetary gear arrangement 1118 which is connected with the engine andtorque converter 12 through the input shaft 17 and with the final drivemechanism 16 through the output shaft 19. The planetary gear arrangement1118 includes three planetary gear sets 1120, 1130 and 1140.

The planetary gear set 1120 includes a sun gear member 1122, a ring gearmember 1124, and a planet carrier assembly 1126. The planet carrierassembly 1126 includes a plurality of pinion gears 1127 rotatablymounted on a carrier member 1129 and disposed in meshing relationshipwith both the sun gear member 1122 and the ring gear member 1124.

The planetary gear set 1130 includes a sun gear member 1132, a ring gearmember 1134, and a planet carrier assembly member 1136. The planetcarrier assembly member 1136 includes a plurality of intermeshing piniongears 1137 that are rotatably mounted on a carrier member 1139 anddisposed in meshing relationship with both the sun gear member 1132 andthe ring gear member 1134.

The planetary gear set 1140 includes a sun gear member 1142, a ring gearmember 1144, and a planet carrier assembly member 1146. The planetcarrier assembly member 1146 includes a plurality of pinion gears 1147rotatably mounted on a carrier member 1149 and disposed in meshingrelationship with both the sun gear member 1142 and the ring gear member1144.

The planetary gear arrangement 1118 also includes sixtorque-transmitting mechanisms 1150, 1152, 1154, 1156, 1158 and 1159.The torque-transmitting mechanisms 1150, 1152, 1154 and 1156 are ofrotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1158 and 1159 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1122, and the output shaft 19 is continuously connected with the ringgear member 1144. The ring gear member 1124 is continuously connectedwith the ring gear member 1134 and with the sun gear member 1142 throughthe interconnecting member 1170.

The ring gear member 1144 is selectively connectable with the sun gearmember 1142 through the clutch 1150. The planet carrier assembly member1126 is selectively connectable with the planet carrier assembly member1136 through the clutch 1152. The planet carrier assembly member 1126 isselectively connectable with the planet carrier assembly member 1146through the clutch 1154. The planet carrier assembly member 1136 isselectively connectable with the ring gear member 1144 through theclutch 1156. The planet carrier assembly member 1136 is selectivelyconnectable with the transmission housing 1160 through brake 1158. Thesun gear member 1132 is selectively connectable with the transmissionhousing 1160 through the brake 1159.

The truth table shown in FIG. 12b describes the engagement sequence andengagement combinations utilized with the present family member toprovide a reverse drive ratio and seven forward speed ratios. The truthtable of FIG. 12b also provides a set of example numbers that can beestablished in the planetary gear arrangement 1118 utilizing the ringgear/sun gear tooth ratios. The R1/S1 value is the ring gear/sun geartooth ratio of the planetary gear set 1120; the R2/S2 value is the ringgear/sun gear tooth ratio of the planetary gear set 1130; and the R3/S3value is the ring gear/sun gear tooth ratio of the planetary gear set1140.

The chart of FIG. 12b describes the ratio steps between adjacent forwardspeed ratios for a seven-speed transmission. These step ratios areestablished utilizing the example speed ratios given in the truth table.As also shown in the truth table, the torque-transmitting mechanisms1152 and 1158 can remain engaged through the neutral condition, therebysimplifying the forward/reverse interchange.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1120. The numerical values of the firstand second forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1120 and 1140. Thenumerical value of the third forward speed ratio is 1. The numericalvalues of the fourth and fifth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1120, 1130 and 1140. The numerical values of the sixth and seventhforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 1120 and 1130.

A powertrain 1210, shown in FIG. 13a, includes the conventional engineand torque converter 12, a planetary transmission 1214, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1214 through theinput shaft 17. The planetary transmission 1214 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1214 includes a planetary gear arrangement 1218that has a first planetary gear set 1220, a second planetary gear set1230, and a third planetary gear set 1240.

The planetary gear set 1220 includes a sun gear member 1222, a ring gearmember 1224, and a planet carrier assembly 1226. The planet carrierassembly 1226 includes a plurality of pinion gears 1227 rotatablymounted on a carrier member 1229 and disposed in meshing relationshipwith both the sun gear member 1222 and the ring gear member 1224.

The planetary gear set 1230 includes a sun gear member 1232, a ring gearmember 1234, and a planet carrier assembly member 1236. The planetcarrier assembly member 1236 includes a plurality of pinion gears 1237rotatably mounted on a carrier member 1239 and disposed in meshingrelationship with both the sun gear member 1232 and the ring gear member1234.

The planetary gear set 1240 includes a sun gear member 1242, a ring gearmember 1244, and a planet carrier assembly member 1246. The planetcarrier assembly member 1246 includes a plurality of pinion gears 1247rotatably mounted on a carrier member 1249 and disposed in meshingrelationship with both the sun gear member 1242 and the ring gear member1244.

The planetary gear arrangement 1218 also includes six torquetransmitting mechanisms 1250, 1252, 1254, 1256, 1258 and 1259. Thetorque-transmitting mechanisms 1250, 1252, 1254 and 1256 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1258 and 1259 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1242, and the output shaft 19 is continuously connected with the sungear member 1222. The ring gear member 1224 is continuously connectedwith the planet carrier assembly members 1236 and 1246 through theinterconnecting member 1270.

The ring gear member 1224 is selectively connectable with the sun gearmember 1222 through the clutch 1250. The planet carrier assembly member1226 is selectively connectable with the sun gear member 1242 throughthe clutch 1252. The ring gear member 1234 is selectively connectablewith the sun gear member 1242 through the clutch 1254. The sun gearmember 1232 is selectively connectable with the ring gear member 1244through the clutch 1256. The ring gear member 1234 is selectivelyconnectable with the transmission housing 1260 through the brake 1258.The sun gear member 1232 is selectively connectable with thetransmission housing 1260 through the brake 1259.

The truth table shown in FIG. 13b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 13b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 13b. The R1/S1 value is the tooth ratio for the planetary gear set1220; the R2/S2 value is the tooth ratio for the planetary gear set1230; and the R3/S3 value is the tooth ratio for the planetary gear set1240. Also given in FIG. 13b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1230 and 1240. The numerical value ofthe first forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1240. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1230. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1220 and 1230. The numerical value ofthe fifth forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1220 and 1240. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1220. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1220, 1230 and 1240.

A powertrain 1310, shown in FIG. 14a, includes the conventional engineand torque converter 12, a planetary transmission 1314, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1314 through theinput shaft 17. The planetary transmission 1314 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1314 includes a planetary gear arrangement 1318that has a first planetary gear set 1320, a second planetary gear set1330, and a third planetary gear set 1340.

The planetary gear set 1320 includes a sun gear member 1322, a ring gearmember 1324, and a planet carrier assembly 1326. The planet carrierassembly 1326 includes a plurality of pinion gears 1327 rotatablymounted on a carrier member 1329 and disposed in meshing relationshipwith both the sun gear member 1322 and the ring gear member 1324.

The planetary gear set 1330 includes a sun gear member 1332, a ring gearmember 1334, and a planet carrier assembly member 1336. The planetcarrier assembly member 1336 includes a plurality of pinion gears 1337rotatably mounted on a carrier member 1339 and disposed in meshingrelationship with both the sun gear member 1332 and the ring gear member1334.

The planetary gear set 1340 includes a sun gear member 1342, a ring gearmember 1344, and a planet carrier assembly member 1346. The planetcarrier assembly member 1346 includes a plurality of pinion gears 1347rotatably mounted on a carrier member 1349 and disposed in meshingrelationship with both the sun gear member 1342 and the ring gear member1344.

The planetary gear arrangement 1318 also includes six torquetransmitting mechanisms 1350, 1352, 1354, 1356, 1358 and 1359. Thetorque-transmitting mechanisms 1350, 1352, 1354 and 1356 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1358 and 1359 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the ring gear member1344, and the output shaft 19 is continuously connected with the sungear member 1322. The ring gear member 1324 is continuously connectedwith the ring gear member 1334 and the planet carrier assembly member1346 through the interconnecting member 1370.

The ring gear member 1324 is selectively connectable with the sun gearmember 1322 through the clutch 1350. The planet carrier assembly member1326 is selectively connectable with the ring gear member 1344 throughthe clutch 1352. The sun gear member 1332 is selectively connectablewith the ring gear member 1344 through the clutch 1354. The sun gearmember 1332 is selectively connectable with the sun gear member 1342through the clutch 1356. The sun gear member 1332 is selectivelyconnectable with the transmission housing 1360 through the brake 1358.The planet carrier assembly member 1336 is selectively connectable withthe transmission housing 1360 through the brake 1359.

The truth table shown in FIG. 14b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 14b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 14b. The R1/S1 value is the tooth ratio for the planetary gearset 1320; the R2/S2 value is the tooth ratio for the planetary gear set1330; and the R3/S3 value is the tooth ratio for the planetary gear set1340. Also given in FIG. 14b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1330. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1330 and 1340. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1340. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1320 and 1340. The numerical value ofthe fifth forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1320, 1330 and 1340. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1320. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1320 and 1330.

A powertrain 1410, shown in FIG. 15a, includes the conventional engineand torque converter 12, a planetary transmission 1414, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1414 through theinput shaft 17. The planetary transmission 1414 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1414 includes a planetary gear arrangement 1418that has a first planetary gear set 1420, a second planetary gear set1430, and a third planetary gear set 1440.

The planetary gear set 1420 includes a sun gear member 1422, a ring gearmember 1424, and a planet carrier assembly 1426. The planet carrierassembly 1426 includes a plurality of pinion gears 1427 rotatablymounted on a carrier member 1429 and disposed in meshing relationshipwith both the sun gear member 1422 and the ring gear member 1424.

The planetary gear set 1430 includes a sun gear member 1432, a ring gearmember 1434, and a planet carrier assembly member 1436. The planetcarrier assembly member 1436 includes a plurality of pinion gears 1437rotatably mounted on a carrier member 1439 and disposed in meshingrelationship with both the sun gear member 1432 and the ring gear member1434.

The planetary gear set 1440 includes a sun gear member 1442, a ring gearmember 1444, and a planet carrier assembly member 1446. The planetcarrier assembly member 1446 includes a plurality of pinion gears 1447rotatably mounted on a carrier member 1449 and disposed in meshingrelationship with both the sun gear member 1442 and the ring gear member1444.

The planetary gear arrangement 1418 also includes six torquetransmitting mechanisms 1450, 1452, 1454, 1456, 1458 and 1459. Thetorque-transmitting mechanisms 1450, 1452, 1454 and 1456 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1458 and 1459 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1442, and the output shaft 19 is continuously connected with the sungear member 1422. The ring gear member 1424 is continuously connectedwith the planet carrier assembly member 1436 and the ring gear member1444 through the interconnecting member 1470.

The ring gear member 1424 is selectively connectable with the sun gearmember 1422 through the clutch 1450. The planet carrier assembly member1426 is selectively connectable with the sun gear member 1442 throughthe clutch 1452. The sun gear member 1442 is selectively connectablewith the ring gear member 1434 through the clutch 1454. The planetcarrier assembly member 1446 is selectively connectable with the ringgear member 1434 through the clutch 1456. The ring gear member 1434 isselectively connectable with the transmission housing 1460 through thebrake 1458. The sun gear member 1432 is selectively connectable with thetransmission housing 1460 through the brake 1459.

The truth table shown in FIG. 15b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 15b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 15b. The R1/S1 value is the tooth ratio for the planetary gearset 1420; the R2/S2 value is the tooth ratio for the planetary gear set1430; and the R3/S3 value is the tooth ratio for the planetary gear set1440. Also given in FIG. 15b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1440. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1430 and 1440. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1430. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1420 and 1430. The numerical value ofthe fifth forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1420, 1430 and 1440. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1420. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1420 and 1040.

A powertrain 1510, shown in FIG. 16a, includes the conventional engineand torque converter 12, a planetary transmission 1514, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1514 through theinput shaft 17. The planetary transmission 1514 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1514 includes a planetary gear arrangement 1518that has a first planetary gear set 1520, a second planetary gear set1530, and a third planetary gear set 1540.

The planetary gear set 1520 includes a sun gear member 1522, a ring gearmember 1524, and a planet carrier assembly 1526. The planet carrierassembly 1526 includes a plurality of pinion gears 1527 rotatablymounted on a carrier member 1529 and disposed in meshing relationshipwith both the sun gear member 1522 and the ring gear member 1524.

The planetary gear set 1530 includes a sun gear member 1532, a ring gearmember 1534, and a planet carrier assembly member 1536. The planetcarrier assembly member 1536 includes a plurality of pinion gears 1537rotatably mounted on a carrier member 1539 and disposed in meshingrelationship with both the sun gear member 1532 and the ring gear member1534.

The planetary gear set 1540 includes a sun gear member 1542, a ring gearmember 1544, and a planet carrier assembly member 1546. The planetcarrier assembly member 1546 includes a plurality of pinion gears 1547rotatably mounted on a carrier member 1549 and disposed in meshingrelationship with both the sun gear member 1542 and the ring gear member1544.

The planetary gear arrangement 1518 also includes six torquetransmitting mechanisms 1550, 1552, 1554, 1556, 1558 and 1559. Thetorque-transmitting mechanisms 1550, 1552, 1554 and 1556 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1558 and 1559 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the planet carrierassembly member 1536, and the output shaft 19 is continuously connectedwith the planet carrier assembly member 1546. The sun gear member 1522is continuously connected with the sun gear member 1532 and the ringgear member 1544 through the interconnecting member 1570.

The ring gear member 1524 is selectively connectable with the sun gearmember 1522 through the clutch 1550. The ring gear member 1524 isselectively connectable with the planet carrier assembly member 1536through the clutch 1552. The sun gear member 1542 is selectivelyconnectable with the planet carrier assembly member 1526 through theclutch 1554. The planet carrier assembly member 1546 is selectivelyconnectable with the planet carrier assembly member 1526 through theclutch 1556. The ring gear member 1534 is selectively connectable withthe transmission housing 1560 through the brake 1558. The sun gearmember 1542 is selectively connectable with the transmission housing1560 through the brake 1559.

The truth table shown in FIG. 16b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 16b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 16b. The R1/S1 value is the tooth ratio for the planetary gearset 1520; the R2/S2 value is the tooth ratio for the planetary gear set1530; and the R3/S3 value is the tooth ratio for the planetary gear set1540. Also given in FIG. 16b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse and third forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1520 and 1540. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1540. Thenumerical value of the second forward speed ratio is 1. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1520 and 1530. Thenumerical value of the fifth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 1530 and1540. The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1520, 1530 and 1540. The numerical value of the seventh forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 1530.

A powertrain 1610, shown in FIG. 17a, includes the conventional engineand torque converter 12, a planetary transmission 1614, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1614 through theinput shaft 17. The planetary transmission 1614 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1614 includes a planetary gear arrangement 1618that has a first planetary gear set 1620, a second planetary gear set1630, and a third planetary gear set 1640.

The planetary gear set 1620 includes a sun gear member 1622, a ring gearmember 1624, and a planet carrier assembly 1626. The planet carrierassembly 1626 includes a plurality of pinion gears 1627 rotatablymounted on a carrier member 1629 and disposed in meshing relationshipwith both the sun gear member 1622 and the ring gear member 1624.

The planetary gear set 1630 includes a sun gear member 1632, a ring gearmember 1634, and a planet carrier assembly member 1636. The planetcarrier assembly member 1636 includes a plurality of pinion gears 1637rotatably mounted on a carrier member 1639 and disposed in meshingrelationship with both the sun gear member 1632 and the ring gear member1634.

The planetary gear set 1640 includes a sun gear member 1642, a ring gearmember 1644, and a planet carrier assembly member 1646. The planetcarrier assembly member 1646 includes a plurality of pinion gears 1647rotatably mounted on a carrier member 1649 and disposed in meshingrelationship with both the sun gear member 1642 and the ring gear member1644.

The planetary gear arrangement 1618 also includes six torquetransmitting mechanisms 1650, 1652, 1654, 1656, 1658 and 1659. Thetorque-transmitting mechanisms 1650, 1652, 1654 and 1656 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1658 and 1659 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1642, and the output shaft 19 is continuously connected with the sungear member 1622. The ring gear member 1624 is continuously connectedwith the ring gear member 1634 and the planet carrier assembly member1646 through the interconnecting member 1670.

The ring gear member 1624 is selectively connectable with the sun gearmember 1622 through the clutch 1650. The planet carrier assembly member1626 is selectively connectable with the sun gear member 1642 throughthe clutch 1652. The planet carrier assembly member 1636 is selectivelyconnectable with the ring gear member 1644 through the clutch 1654. Thesun gear member 1632 is selectively connectable with the sun gear member1642 through the clutch 1656. The planet carrier assembly member 1636 isselectively connectable with the transmission housing 1660 through thebrake 1658. The sun gear member 1632 is selectively connectable with thetransmission housing 1660 through the brake 1659.

The truth table shown in FIG. 17b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 17b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 17b. The R1/S1 value is the tooth ratio for the planetary gearset 1620; the R2/S2 value is the tooth ratio for the planetary gear set1630; and the R3/S3 value is the tooth ratio for the planetary gear set1640. Also given in FIG. 17b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1630. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1640. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1630 and 1640. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1620, 1630 and 1640. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1620 and 1640. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1620. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1620 and 1630.

A powertrain 1710, shown in FIG. 18a, includes the conventional engineand torque converter 12, a planetary transmission 1714, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1714 through theinput shaft 17. The planetary transmission 1714 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1714 includes a planetary gear arrangement 1718that has a first planetary gear set 1720, a second planetary gear set1730, and a third planetary gear set 1740.

The planetary gear set 1720 includes a sun gear member 1722, a ring gearmember 1724, and a planet carrier assembly 1726. The planet carrierassembly 1726 includes a plurality of pinion gears 1727 rotatablymounted on a carrier member 1729 and disposed in meshing relationshipwith both the sun gear member 1722 and the ring gear member 1724.

The planetary gear set 1730 includes a sun gear member 1732, a ring gearmember 1734, and a planet carrier assembly member 1736. The planetcarrier assembly member 1736 includes a plurality of pinion gears 1737rotatably mounted on a carrier member 1739 and disposed in meshingrelationship with both the sun gear member 1732 and the ring gear member1734.

The planetary gear set 1740 includes a sun gear member 1742, a ring gearmember 1744, and a planet carrier assembly member 1746. The planetcarrier assembly member 1746 includes a plurality of pinion gears 1747and 1748 rotatably mounted on a carrier member 1749 and disposed inmeshing relationship with both the sun gear member 1742 and the ringgear member 1744.

The planetary gear arrangement 1718 also includes six torquetransmitting mechanisms 1750, 1752, 1754, 1756, 1758 and 1759. Thetorque-transmitting mechanisms 1750, 1752, 1754 and 1756 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1758 and 1759 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1742, and the output shaft 19 is continuously connected with the sungear member 1732. The ring gear member 1724 is continuously connectedwith the ring gear members 1734 and 1744 through the interconnectingmember 1770.

The ring gear member 1734 is selectively connectable with the sun gearmember 1732 through the clutch 1750. The sun gear member 1722 isselectively connectable with the sun gear member 1742 through the clutch1752. The planet carrier assembly member 1726 is selectively connectablewith the planet carrier assembly member 1746 through the clutch 1754.The planet carrier assembly member 1736 is selectively connectable withthe sun gear member 1742 through the clutch 1756. The sun gear member1722 is selectively connectable with the transmission housing 1760through the brake 1758. The planet carrier assembly member 1726 isselectively connectable with the transmission housing 1760 through thebrake 1759.

The truth table shown in FIG. 18b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 18b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 18b. The R1/S1 value is the tooth ratio for the planetary gear set1720; the R2/S2 value is the tooth ratio for the planetary gear set1730; and the R3/S3 value is the tooth ratio for the planetary gear set1740. Also given in FIG. 18b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1720. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1740. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1720 and 1740. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1720, 1730 and 1740. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1730 and 1740. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1730. Thenumerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1720 and 1730.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

What is claimed is:
 1. A multi-speed transmission comprising: an inputshaft; an output shaft; first, second and third planetary gear sets eachhaving first, second and third members; said input shaft beingcontinuously interconnected with a member of said planetary gear sets,and said output shaft being continuously interconnected with anothermember of said planetary gear sets; an interconnecting membercontinuously interconnecting said first member of said first planetarygear set and said first member of said second planetary gear set andsaid first member of said third planetary gear set; a firsttorque-transmitting mechanism selectively interconnecting a member ofsaid first, second or third planetary gear set with a stationary member;a second torque-transmitting mechanism selectively interconnecting saidsecond member of said first planetary gear set with a member of saidsecond or third planetary gear set; a third torque-transmittingmechanism selectively interconnecting said second member of said secondplanetary gear set with a member of said first or third planetary gearset; a fourth torque-transmitting mechanism selectively interconnectingsaid second member of said third planetary gear set with a member ofsaid first or second planetary gear set; a fifth torque-transmittingmechanism selectively interconnecting a member of said first or secondplanetary gear set with another member of said first, second or thirdplanetary gear set or with said stationary member; a sixthtorque-transmitting mechanism selectively interconnecting a member ofsaid first, second or third planetary gear set with another member ofsaid planetary gear sets, or with said stationary member; and saidtorque-transmitting mechanisms being engaged in combinations of three toestablish at least seven forward speed ratios and a reverse speed ratiobetween said input shaft and said output shaft.
 2. The transmissiondefined in claim 1, wherein said second, third, fourth, fifth and sixthtorque-transmitting mechanisms comprise clutches.
 3. The transmissiondefined in claim 1, wherein said second, third, fourth and fifthtorque-transmitting mechanisms comprise clutches and said first andsixth torque-transmitting mechanisms comprise brakes.
 4. Thetransmission defined in claim 1, wherein said second, third and fourthtorque-transmitting mechanisms comprise clutches, and said first, fifthand sixth torque-transmitting mechanisms comprise brakes.
 5. Thetransmission defined in claim 1, wherein planet carrier assembly membersof each of said planetary gear sets are single-pinion carriers.
 6. Thetransmission defined in claim 1, wherein at least one planet carrierassembly member of said planetary gear sets is a double-pinion carrier.7. A multi-speed transmission comprising: an input shaft; an outputshaft; a planetary gear arrangement having first, second and thirdplanetary gear sets, each planetary gear set having first, second andthird members; said input shaft being continuously interconnected with amember of said planetary gear sets, and said output shaft beingcontinuously interconnected with another member of said planetary gearsets; an interconnecting member continuously interconnecting said firstmember of said first planetary gear set and said first member of saidsecond planetary gear set and said first member of said third planetarygear set; six torque-transmitting mechanisms for selectivelyinterconnecting said members to establish combinations of members joinedfor common rotation, said six torque-transmitting mechanisms beingengaged in combinations of three to establish at least seven forwardspeed ratios and one reverse speed ratio between said input shaft andsaid output shaft.
 8. The transmission defined in claim 7, wherein afirst of said six torque-transmitting mechanisms is operable forselectively connecting a member of said first, second or third planetarygear set with said transmission housing.
 9. The transmission defined inclaim 7, wherein a second of said six torque-transmitting mechanisms isoperable for selectively interconnecting said second member of saidfirst planetary gear set with a member of said second or third planetarygear set.
 10. The transmission defined in claim 7, wherein a third ofsaid six torque-transmitting mechanisms is operable for selectivelyinterconnecting said second member of said second planetary gear setwith a member of said first or third planetary gear.
 11. Thetransmission defined in claim 7, wherein a fourth of said sixtorque-transmitting mechanisms is selectively operable forinterconnecting a said second member of said third planetary gear setwith a member of said first or second planetary gear set.
 12. Thetransmission defined in claim 7, wherein a fifth of said sixtorque-transmitting mechanisms is selectively operable forinterconnecting a member of said first or second planetary gear set withanother member of said first, second or third planetary gear set, orwith said transmission housing.
 13. The transmission defined in claim 7,wherein a sixth of said six torque-transmitting mechanisms selectivelyinterconnects a member of said first, second or third planetary gear setwith another member of said planetary gear sets, or with saidtransmission housing.
 14. The transmission in claim 7, wherein planetcarrier assembly members of each of said planetary gear sets aresingle-pinion carriers.
 15. The transmission in claim 7, wherein atleast one planet carrier assembly member of said planetary gear sets isa double-pinion carrier.